Bad Checksum on i386-current
Hi Misc@, Could someone elaborate me with this tcpdump I had? After nat-ing, checksum error shows, on the same packet.. rule 173.home.8/(match) [uid 0, pid 9731] pass in on vlan516: 172.16.33.254.64264 188.255.110.14.51413: S [tcp sum ok] 260322197:260322197(0) win 8192 mss 1436,nop,nop,sackOK [tos 0x28] (ttl 126, id 5689, len 48) rule 173.home.13/(match) [uid 0, pid 9731] pass out on vlan500: [orig src 172.16.33.254:64264, dst 188.255.110.14:51413] 202.90.195.234.59074 188.255.110.14.51413: S [bad tcp cksum f54!] 260322197:260322197(0) win 8192 mss 1436,nop,nop,sackOK [tos 0x28] (ttl 125, id 5689, len 48, bad cksum 2d4b!) Thanks, Insan Praja dmesg: OpenBSD 5.1 (GENERIC.MP) #15: Fri Feb 10 01:01:43 WIT 2012 r...@core01.netaplus.net:/usr/src/sys/arch/i386/compile/GENERIC.MP RTC BIOS diagnostic error 80clock_battery cpu0: Intel(R) Xeon(R) CPU X3430 @ 2.40GHz (GenuineIntel 686-class) 2.40 GHz cpu0: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,NXE,LONG,SSE3,MWAIT,DS-CPL,VMX,SMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT,LAHF real mem = 2135588864 (2036MB) avail mem = 2090528768 (1993MB) mainbus0 at root bios0 at mainbus0: AT/286+ BIOS, date 07/23/10, BIOS32 rev. 0 @ 0xfd7e1, SMBIOS rev. 2.5 @ 0x7f6b9000 (55 entries) bios0: vendor IBM Corp. version -[GYE144AUS-1.09]- date 12/16/2010 bios0: IBM 81Y6793 acpi0 at bios0: rev 2 acpi0: sleep states S0 S1 S5 acpi0: tables DSDT FACP TCPA APIC MCFG SLIC HPET SSDT SSDT ERST DMAR acpi0: wakeup devices PCIB(S4) POP3(S4) POP1(S4) POP6(S4) POP5(S4) PEX1(S4) PEX2(S4) PEX3(S4) PEX4(S4) PEX5(S4) EHI1(S3) EHI2(S3) PWRB(S3) acpitimer0 at acpi0: 3579545 Hz, 24 bits acpimadt0 at acpi0 addr 0xfee0: PC-AT compat cpu0 at mainbus0: apid 0 (boot processor) cpu0: apic clock running at 132MHz cpu1 at mainbus0: apid 2 (application processor) cpu1: Intel(R) Xeon(R) CPU X3430 @ 2.40GHz (GenuineIntel 686-class) 2.40 GHz cpu1: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,NXE,LONG,SSE3,MWAIT,DS-CPL,VMX,SMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT,LAHF cpu2 at mainbus0: apid 4 (application processor) cpu2: Intel(R) Xeon(R) CPU X3430 @ 2.40GHz (GenuineIntel 686-class) 2.40 GHz cpu2: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,NXE,LONG,SSE3,MWAIT,DS-CPL,VMX,SMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT,LAHF cpu3 at mainbus0: apid 6 (application processor) cpu3: Intel(R) Xeon(R) CPU X3430 @ 2.40GHz (GenuineIntel 686-class) 2.40 GHz cpu3: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,NXE,LONG,SSE3,MWAIT,DS-CPL,VMX,SMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT,LAHF ioapic0 at mainbus0: apid 8 pa 0xfec0, version 20, 24 pins acpimcfg0 at acpi0 addr 0x8000, bus 0-255 acpihpet0 at acpi0: 14318179 Hz acpiprt0 at acpi0: bus 0 (PCI0) acpiprt1 at acpi0: bus 36 (PCIB) acpiprt2 at acpi0: bus 26 (POP3) acpiprt3 at acpi0: bus -1 (POP1) acpiprt4 at acpi0: bus -1 (POP6) acpiprt5 at acpi0: bus 31 (POP5) acpiprt6 at acpi0: bus 1 (PEX1) acpiprt7 at acpi0: bus 6 (PEX2) acpiprt8 at acpi0: bus 11 (PEX3) acpiprt9 at acpi0: bus 16 (PEX4) acpiprt10 at acpi0: bus 21 (PEX5) acpicpu0 at acpi0: PSS acpicpu1 at acpi0: PSS acpicpu2 at acpi0: PSS acpicpu3 at acpi0: PSS acpibtn0 at acpi0: PWRB bios0: ROM list: 0xc/0x8000 0xc8000/0x1000 0xc9000/0x1000 0xca000/0x1000 ipmi at mainbus0 not configured cpu0: Enhanced SpeedStep 2394 MHz: speeds: 2394, 2261, 2128, 1995, 1862, 1729, 1596, 1463, 1330, 1197 MHz pci0 at mainbus0 bus 0: configuration mode 1 (bios) pchb0 at pci0 dev 0 function 0 Intel Core DMI rev 0x11 ppb0 at pci0 dev 3 function 0 Intel Core PCIE rev 0x11: apic 8 int 16 pci1 at ppb0 bus 26 ppb1 at pci0 dev 5 function 0 Intel Core PCIE rev 0x11: apic 8 int 16 pci2 at ppb1 bus 31 em0 at pci2 dev 0 function 0 Intel I340-T2 (82580) rev 0x01: msi, address 00:1b:21:90:00:d0 em1 at pci2 dev 0 function 1 Intel I340-T2 (82580) rev 0x01: msi, address 00:1b:21:90:00:d1 Intel Core Management rev 0x11 at pci0 dev 8 function 0 not configured Intel Core Scratch rev 0x11 at pci0 dev 8 function 1 not configured Intel Core Control rev 0x11 at pci0 dev 8 function 2 not configured Intel Core Misc rev 0x11 at pci0 dev 8 function 3 not configured Intel Core QPI Link rev 0x11 at pci0 dev 16 function 0 not configured Intel Core QPI Routing rev 0x11 at pci0 dev 16 function 1 not configured ehci0 at pci0 dev 26 function 0 Intel 3400 USB rev 0x05: apic 8 int 19 usb0 at ehci0: USB revision 2.0 uhub0 at usb0 Intel EHCI root hub rev 2.00/1.00 addr 1 ppb2 at pci0 dev 28 function 0 Intel 3400 PCIE rev 0x05: apic 8 int 17 pci3 at ppb2 bus 1 ppb3 at pci0 dev 28 function 4 Intel 3400 PCIE rev 0x05: apic 8 int 17 pci4 at ppb3 bus 6 ppb4 at pci4 dev 0
Re: Bad Checksum on i386-current
On Sat, Feb 11, 2012 at 12:43 PM, Insan Praja SW insan.pr...@gmail.com wrote: Hi Misc@, Could someone elaborate me with this tcpdump I had? After nat-ing, checksum error shows, on the same packet.. rule 173.home.8/(match) [uid 0, pid 9731] pass in on vlan516: 172.16.33.254.64264 188.255.110.14.51413: S [tcp sum ok] 260322197:260322197(0) win 8192 mss 1436,nop,nop,sackOK [tos 0x28] (ttl 126, id 5689, len 48) rule 173.home.13/(match) [uid 0, pid 9731] pass out on vlan500: [orig src 172.16.33.254:64264, dst 188.255.110.14:51413] 202.90.195.234.59074 188.255.110.14.51413: S [bad tcp cksum f54!] 260322197:260322197(0) win 8192 mss 1436,nop,nop,sackOK [tos 0x28] (ttl 125, id 5689, len 48, bad cksum 2d4b!) from man tcpdump IP Checksum Offload Some network cards support IP checksum offload. Packet headers for such interfaces erroneously indicate a bad checksum, since the checksum is not calculated until after tcpdump sees the packet. so maybe related to your case Thanks, Insan Praja dmesg: OpenBSD 5.1 (GENERIC.MP) #15: Fri Feb 10 01:01:43 WIT 2012 B B r...@core01.netaplus.net:/usr/src/sys/arch/i386/compile/GENERIC.MP RTC BIOS diagnostic error 80clock_battery cpu0: Intel(R) Xeon(R) CPU X3430 @ 2.40GHz (GenuineIntel 686-class) 2.40 GHz cpu0: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,NXE,LONG,SSE3,MWAIT,DS-CPL,VMX,SMX, EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT,LAHF real mem B = 2135588864 (2036MB) avail mem = 2090528768 (1993MB) mainbus0 at root bios0 at mainbus0: AT/286+ BIOS, date 07/23/10, BIOS32 rev. 0 @ 0xfd7e1, SMBIOS rev. 2.5 @ 0x7f6b9000 (55 entries) bios0: vendor IBM Corp. version -[GYE144AUS-1.09]- date 12/16/2010 bios0: IBM 81Y6793 acpi0 at bios0: rev 2 acpi0: sleep states S0 S1 S5 acpi0: tables DSDT FACP TCPA APIC MCFG SLIC HPET SSDT SSDT ERST DMAR acpi0: wakeup devices PCIB(S4) POP3(S4) POP1(S4) POP6(S4) POP5(S4) PEX1(S4) PEX2(S4) PEX3(S4) PEX4(S4) PEX5(S4) EHI1(S3) EHI2(S3) PWRB(S3) acpitimer0 at acpi0: 3579545 Hz, 24 bits acpimadt0 at acpi0 addr 0xfee0: PC-AT compat cpu0 at mainbus0: apid 0 (boot processor) cpu0: apic clock running at 132MHz cpu1 at mainbus0: apid 2 (application processor) cpu1: Intel(R) Xeon(R) CPU X3430 @ 2.40GHz (GenuineIntel 686-class) 2.40 GHz cpu1: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,NXE,LONG,SSE3,MWAIT,DS-CPL,VMX,SMX, EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT,LAHF cpu2 at mainbus0: apid 4 (application processor) cpu2: Intel(R) Xeon(R) CPU X3430 @ 2.40GHz (GenuineIntel 686-class) 2.40 GHz cpu2: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,NXE,LONG,SSE3,MWAIT,DS-CPL,VMX,SMX, EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT,LAHF cpu3 at mainbus0: apid 6 (application processor) cpu3: Intel(R) Xeon(R) CPU X3430 @ 2.40GHz (GenuineIntel 686-class) 2.40 GHz cpu3: FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUS H,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,NXE,LONG,SSE3,MWAIT,DS-CPL,VMX,SMX, EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,POPCNT,LAHF ioapic0 at mainbus0: apid 8 pa 0xfec0, version 20, 24 pins acpimcfg0 at acpi0 addr 0x8000, bus 0-255 acpihpet0 at acpi0: 14318179 Hz acpiprt0 at acpi0: bus 0 (PCI0) acpiprt1 at acpi0: bus 36 (PCIB) acpiprt2 at acpi0: bus 26 (POP3) acpiprt3 at acpi0: bus -1 (POP1) acpiprt4 at acpi0: bus -1 (POP6) acpiprt5 at acpi0: bus 31 (POP5) acpiprt6 at acpi0: bus 1 (PEX1) acpiprt7 at acpi0: bus 6 (PEX2) acpiprt8 at acpi0: bus 11 (PEX3) acpiprt9 at acpi0: bus 16 (PEX4) acpiprt10 at acpi0: bus 21 (PEX5) acpicpu0 at acpi0: PSS acpicpu1 at acpi0: PSS acpicpu2 at acpi0: PSS acpicpu3 at acpi0: PSS acpibtn0 at acpi0: PWRB bios0: ROM list: 0xc/0x8000 0xc8000/0x1000 0xc9000/0x1000 0xca000/0x1000 ipmi at mainbus0 not configured cpu0: Enhanced SpeedStep 2394 MHz: speeds: 2394, 2261, 2128, 1995, 1862, 1729, 1596, 1463, 1330, 1197 MHz pci0 at mainbus0 bus 0: configuration mode 1 (bios) pchb0 at pci0 dev 0 function 0 Intel Core DMI rev 0x11 ppb0 at pci0 dev 3 function 0 Intel Core PCIE rev 0x11: apic 8 int 16 pci1 at ppb0 bus 26 ppb1 at pci0 dev 5 function 0 Intel Core PCIE rev 0x11: apic 8 int 16 pci2 at ppb1 bus 31 em0 at pci2 dev 0 function 0 Intel I340-T2 (82580) rev 0x01: msi, address 00:1b:21:90:00:d0 em1 at pci2 dev 0 function 1 Intel I340-T2 (82580) rev 0x01: msi, address 00:1b:21:90:00:d1 Intel Core Management rev 0x11 at pci0 dev 8 function 0 not configured Intel Core Scratch rev 0x11 at pci0 dev 8 function 1 not configured Intel Core Control rev 0x11 at pci0 dev 8 function 2 not configured Intel Core Misc rev 0x11 at pci0 dev 8 function 3 not configured Intel Core QPI Link rev 0x11 at pci0 dev 16 function 0 not configured Intel Core QPI Routing rev 0x11
Re: Bad Checksum on i386-current
On 11 February 2012 11:00, Tomas Bodzar tomas.bod...@gmail.com wrote:
On Sat, Feb 11, 2012 at 12:43 PM, Insan Praja SW insan.pr...@gmail.com
wrote:
Hi Misc@,
Could someone elaborate me with this tcpdump I had? After nat-ing,
checksum
error shows, on the same packet..
rule 173.home.8/(match) [uid 0, pid 9731] pass in on vlan516:
172.16.33.254.64264 188.255.110.14.51413: S [tcp sum ok]
260322197:260322197(0) win 8192 mss 1436,nop,nop,sackOK [tos 0x28] (ttl
126, id 5689, len 48)
rule 173.home.13/(match) [uid 0, pid 9731] pass out on vlan500: [orig src
172.16.33.254:64264, dst 188.255.110.14:51413] 202.90.195.234.59074
188.255.110.14.51413: S [bad tcp cksum f54!] 260322197:260322197(0) win
8192
mss 1436,nop,nop,sackOK [tos 0x28] (ttl 125, id 5689, len 48, bad cksum
2d4b!)
from man tcpdump
IP Checksum Offload
Some network cards support IP checksum offload. Packet headers for
such
interfaces erroneously indicate a bad checksum, since the checksum is
not
calculated until after tcpdump sees the packet.
so maybe related to your case
I think that is not the case here, by default we do not enable em(4)
checksumming offload.
Just to make sure, can you give me the output of 'if config
em{0,1,2,3} hwfeatures' ?
I think pf is not recalculating the checksum after nating, not sure if
it should, henning ?
Re: Bad Checksum on i386-current
On 11 February 2012 09:43, Insan Praja SW insan.pr...@gmail.com wrote: Hi Misc@, Could someone elaborate me with this tcpdump I had? After nat-ing, checksum error shows, on the same packet.. rule 173.home.8/(match) [uid 0, pid 9731] pass in on vlan516: 172.16.33.254.64264 188.255.110.14.51413: S [tcp sum ok] 260322197:260322197(0) win 8192 mss 1436,nop,nop,sackOK [tos 0x28] (ttl 126, id 5689, len 48) rule 173.home.13/(match) [uid 0, pid 9731] pass out on vlan500: [orig src 172.16.33.254:64264, dst 188.255.110.14:51413] 202.90.195.234.59074 188.255.110.14.51413: S [bad tcp cksum f54!] 260322197:260322197(0) win 8192 mss 1436,nop,nop,sackOK [tos 0x28] (ttl 125, id 5689, len 48, bad cksum 2d4b!) Obvious question I missed, do they reach the other host with wrong checksums ?
Re: Bad Checksum on i386-current
* Christiano F. Haesbaert haesba...@haesbaert.org [2012-02-11 14:25]: I think pf is not recalculating the checksum after nating, not sure if it should, henning ? ip_output does that unconditionally, and i fixed the bridge to do that too -- Henning Brauer, h...@bsws.de, henn...@openbsd.org BS Web Services, http://bsws.de, Full-Service ISP Secure Hosting, Mail and DNS Services. Dedicated Servers, Root to Fully Managed Henning Brauer Consulting, http://henningbrauer.com/
